MOSUL, Iraq (AFP) -- A Christian was killed in the restive city of Mosul on Tuesday, the third in as many days, as community leaders warned of rising violence against the minority ahead of Iraq's March 7 general election.

Christian leaders in Mosul, north of Baghdad, have criticised the security forces for "standing by and watching" as attacks against their community increase in the run-up to the parliamentary poll.

On Tuesday, a gunman emerged from a car in the north of the city and fired at two Christian students with an automatic weapon, according to a police officer who did not want to be named.

The shooter fled together with two other men in the car.

The officer said that Zia Toma, a 21-year-old engineering student, was killed and Ramsin Shmael, a 22-year-old pharmacy student, wounded. Both young men were Assyrian Christians.

"We don't want elections, we don't want representatives, we don't want our rights, we just want to be alive," said Baasil Abdul Noor, a priest at Mar Behnam church in Al-Arabi neighbourhood where the shooting occurred.

"It has become a nightmare. The security forces should not be standing by and watching. We hold them responsible, because they are supposed to be protecting us, and protecting all Iraqis."

Also in Mosul on Tuesday, two policemen were killed and nine other people wounded as a car bomb hit a police forensics bureau, emergency services said.

Tuesday's murder of the student came after gunmen in Mosul killed two shop owners from Iraq's Christian minority in separate attacks, prompting community leaders to criticise the security forces.

Greengrocer Fatukhi Munir, an Assyrian Catholic, was gunned down inside his shop in a drive-by shooting late on Monday, and armed assailants killed Rayan Salem Elias, a Chaldean Christian, outside his home on Sunday.

"I condemn this organised campaign against Christians," said Yahya Abid Mahsoob, human rights committee chair of the provincial council of Nineveh, of which Mosul is the capital.

"We (the provincial council) call upon the local and central government to take all precautions to protect Christians."

Others have expressed concerns that Christians could be targeted in violence ahead of the elections seen as a key test of reconciliation in Iraq, which has been wracked by sectarian hostilities since the 2003 US-led invasion.

"The Christian minority has become an issue in the elections, as it always is before elections," said Hazem Girgis, a deacon at an Orthodox church in the town centre.

"We are terrified... and the security forces are not able to offer us any security," said Girgis.

Attacks occur on a regular basis in Mosul and surrounding Nineveh province, which is among Iraq's most violent areas.

Human Rights Watch warned in November that minorities including Christians in the north were the collateral victims of a conflict between Arabs and Kurds over who controls Iraq's disputed northern provinces.

In late 2008, a systematic campaign of killings and targeted violence killed 40 Christians and saw more than 12,000 others flee Mosul.